This invention relates generally to improvements in manually grasped implements such as a cooking vessel, hair brush, paint brush, sports racquet or bat, hand tool, writing instrument, as well as virtually any other type of manually grasped device having a handle or related substrate for manual grasping or engagement. More specifically, this invention relates to an improved deformable grip responsive to user hand and/or fingertip pressure or the like to assume a highly comfortable and low fatigue geometric configuration.
Manual implements generally incorporate a handle or related structure having a size and shape for appropriate manual grasping and manipulation of the implement during normal intended use. In one common form, the handle structure comprises an elongated rigid element having one end securely connected to the implement, such as a cooking pot or pan, a hair brush, a tool head, etc. In another common form, the manual implement is normally grasped directly about the body thereof, such as in the case of writing and other marking instruments, baseball and softball bats, etc. In either case, a variety of improved grips have been developed in recent years for use with such manual implements, primarily to provide a relatively soft and resilient or cushioned grip structure for enhanced user comfort and improved control of the manual implement during normal use thereof.
In the past, cushioned grip structures for relatively large manual implements such as sports equipment, hand tools, cookware, and hair brushes and the like have generally been limited to relatively soft and resilient rubber or rubber-like elastomer sleeves or sleeve-like wraps mounted onto the implement handle. While such grip structures beneficially provide a degree of cushioning for improved user comfort, the relative deformation of such grip structures during normal use is inherently limited. In other words, such grip structures have generally not provided a high degree of shape deformation needed to assume a customized ergonomical shape conforming closely to the anatomical contours of an individual user""s hand and/or fingers, wherein such customized shape is conducive to substantially optimized user comfort with substantially minimized user fatigue.
In relatively small manual implements such as writing instruments and the like, cushioned grip structures are similarly provided in the form of resilient elastomer sleeves and the like. In some designs, an outer resilient sleeve encloses an internal cavity which is filled with a flowable substance such as a deformable putty or relatively viscous liquid adapted to displace and thereby achieve substantial shape deformation when the grip structure is manually grasped. See, for example, U.S. Pat. No. 5,000,599. Such grip structures can undergo substantial shape deformation to conform closely to the anatomical contours of a particular user""s hand and/or fingertips for enhanced user comfort. However, in grip structures of this type, special attention is required to properly close and seal the internal cavity subsequent to placement of the flowable substance therein, in order to prevent leakage of the flowable substance. Moreover, notwithstanding proper sealing of this internal cavity, backflow leakage of the flowable substance can still occur in the event that the outer sleeve is damaged in a manner forming a small hole or tear therein. Such leakage of the flowable substance not only results in loss of the desired deformable and resilient grip characteristics, but also creates an unsightly and undesirable mess.
The present invention is directed to further improvements in and to deformable grips for use with a wide range of large and small manual implements, wherein the improved deformable grip incorporates a flowable resilient filler material contained within an internal chamber or cavity defined by a resilient outer grip structure such as a sleeve, and further wherein undesired backflow leakage of the filler material is substantially precluded.
In accordance with the invention, an improved deformable grip or cushioned pad is provided for use with a manually grasped or manually engaged implement to provide a soft and resilient structure having the capacity for shape adaptation in conformance with the anatomical contours and particular grasping technique of an individual user. The deformable grip is designed to assume a custom fit configuration when the implement is grasped or gripped by the user for enhanced user comfort and control with reduced fatigue. The deformable grip comprises an outer resilient and flexible grip structure such as an outer sleeve mounted on the implement, as by mounting onto an implement handle, to define and substantially enclose at least one internal chamber or cavity which is filled at least partially with a flowable resilient filler material in the form of a selected quantity of resilient balls having sufficient shape elasticity to provide the sleeve with a selected and deformable tactile feel during normal use. These resilient balls are sufficiently deformable to accommodate injection into the sleeve cavity through a hollow tube or needle passed through a small puncture port formed in the sleeve, followed by return to a normal size and shape sufficiently large to prevent backflow leakage through the puncture port to the sleeve exterior.
In a preferred form, the outer grip structure comprises an outer sleeve having a generally cylindrical component formed from a resilient and flexible silicon-based elastomer or the like. This outer sleeve is formed or otherwise suitably assembled with an inner liner and cooperating therewith to define the at least one internal chamber or cavity of selected size and shape, such as a generally annular cross sectional configuration. In an alternative preferred form, the internal cavity or chamber can be provided in the configuration of one or more localized pads formed at one or more selected positions on the grip structure. The outer sleeve and inner liner are mounted onto the implement such as by mounting onto an elongated implement handle in a selected position for manual grasping during normal use of the implement. The at least one internal chamber is at least partially filled by injecting a selected quantity of the resilient balls under pressure, as by use of syringe or the like, through a hollow injection needle passed through the outer sleeve via a small puncture port or the like formed therein. During this injection step, the resilient balls assume a narrow cross sectional size sufficiently small to pass through the hollow bore of the injection needle, and thus also through the puncture port, into the internal cavity. However, within the internal cavity and upon release of the injection pressure, the resilient balls return substantially to an initial nondeformed state each having a cross sectional size substantially in excess of the puncture port size. As a result, within the internal cavity, the resilient balls assume a size which prevents backflow leakage through the puncture port to the exterior of the outer sleeve, without requiring the puncture port to be sealed. Normal pressure applied via the outer sleeve to the resilient balls during use of the manual implement is inadequate to deform the balls sufficiently for backflow leakage through the puncture port.
In one preferred form, the resilient balls are formed from polyurethane foam each having a diametric size of about {fraction (1/32)} inch. To facilitate injection through the hollow needle into the internal cavity, and to enhance ball flowability in response to manual pressure applied to the deformable drip during normal use, the resilient balls may desirably be coated with a liquid silicon lubricant. During normal use, the puncture port formed in the outer sleeve normally exhibits sufficient self-sealing characteristics to prevent backflow leakage of any significant portion of the lubricant.
Other features and advantages of the invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.